Vascular adhesion protein-1 (hereinafter to be abbreviated as VAP-1) is an amine oxidase (semicarbazide sensitive amine oxidase, SSAO) which is abundant in human plasma, and shows remarkably increased expression in vascular endothelium and vascular smooth muscle of the inflammatory region. While the physiological role of VAP-1 has not been clarified until recently, VAP-1 gene was cloned in 1998, and VAP-1 has been reported to be a membrane protein that regulates rolling and migration of lymphocyte and NK cell as an adhesion molecule under regulation of expression by inflammatory cytokine. Although the amine to be a substrate is unknown, it is considered to be methylamine generated in any part of living organisms. It is also known that hydrogen peroxide and aldehydes produced due to the amine oxidase activity in the molecule are important factors of adhesion activity.
A recent report has documented that VAP-1 enzyme activity in plasma increases in diabetic patients, whether type I or type II, and the increase is particularly remarkable in diabetic patients suffering from retinopathy complications (Diabetologia, 42 (1999) 233–237, Diabetic Medicine, 16 (1999) 514–521).
In addition, it has been reported that VAP-1 is associated with the following diseases:    (1) cirrhosis, essential stabilized hypertension, diabetes, arthrosis (see JP-A-61-239891 and U.S. Pat. No. 4,888,283);    (2) endothelium damage (in diabetes, atherosclerosis and hypertension), a cardiovascular disorder associated with diabetes and uraemia, pain associated with gout and arthritis, retinopathy (in diabetes patients) (see WO 93/23023);    (3) an (connective tissue) inflammatory disease or condition (rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis and osteoarthritis or degenerative joint disease, Reiter's syndrome, Sjögren's syndrome, Behçet's syndrome, relapsing polychondritis, systemic lupus erythematosus, discoid lupus erythematosus, systemic sclerosis, eosinophilic fasciitis, polymyositis, dermatomyositis, polymyalgia rheumatica, vasculitis, temporal arteritis, polyarteritis nodosa, Wegener's granulomatosis, mixed connective tissue disease, and juvenile rheumatoid arthritis); a gastrointestinal inflammatory disease or condition [Crohn's disease, ulcerative colitis, irritable bowel syndrome (spastic colon), fibrotic conditions of the liver, inflammation of the oral mucosa (stomatitis), and recurrent aphtous stomatitis]; a central nervous system inflammatory disease or condition (multiple sclerosis, Alzheimer's disease, and ischaemia-reperfusion injury associated with ischemic stroke); a pulmonary inflammatory disease or condition (asthma, adult respiratory distress syndrome, chronic obstructive pulmonary disease); a (chronic) skin inflammatory disease or condition (psoriasis, allegic lesions, lichen planus, pityriasis rosea, contact dermatitis, atopic dermatitis, pityriasis rubra pilaris); a disease related to carbohydrate metabolism (diabetes and complications from diabetes) including microvascular and macrovascular disease (atherosclerosis, vascular retinopathies, retinopathy, nephropathy, nephrotic syndrome and neuropathy (polyneuropathy, mononeuropathies and autonomic neuropathy), foot ulcers, joint problems, and increased risk of infection); a disease related to aberrations in adipocyte differentiation or function or smooth muscle cell function (atherosclerosis and obesity); a vascular disease [atheromatous ateriosclerosis, nonatheromatous ateriosclerosis, ischemic heart disease including myocardial infarction and peripheral arterial occlusion, Raynaud's disease and phenomenon, thromboangiitis obliterans (Buerger's disease)]; chronic arthritis; inflammatory bowel diseases; skin dermatoses (see WO 02/02090, WO 02/02541 and U.S. patent application publication No. 2002/0173521 A1);    (4) diabetes mellitus (see WO 02/38152); and    (5) SSAO-mediated complication [diabetes (insulin dependent diabetes mellitus (IDDM) and non-insulin dependent diabetes mellitus (NIDDM)) and vascular complication (heart attack, angina, strokes, amputations, blindness and renal failure)] (see WO 02/38153), and the like.
Under the present circumstances, a drug treatment or prophylaxis of the above diseases has been demanded.
Macular edema is a common ocular abnormality resulting from a vast etiology and characterized by perturbation of the integrity of the blood-retinal barrier of the perifoveal capillaries and the optic nerve head. Macular edema is known to include diabetic and non-diabetic ones. Macular edema as a diabetic complication is a disease state that can occur in any stage of diabetic retinopathy, emerges before the onset of neovascularization and causes a serious visual disorder. Macular area is a highly evolved part in retina and plays a key role in controlling the eyesight. Once the macular area suffers from edema, how mild the change may be, it causes a significant failure of eyesight, and when left unattended, the edema causes irreversible changes of macular tissue, and it is considered to encourage progress of retinopathy.
At present, for macular edema, laser beam photocoagulation and vitreous surgery have been tried as a symptomatic therapy. However, irradiation of laser on the macular area is not easy and unnecessary laser treatments may produce side effects (e.g., possible encouragement of edema by causing inflammation). The vitreous surgery is considered to provide effect in 70 percent of macular edema, but physical and economical burden on patients is high, and the incidence of recurrence is also high. These treatment methods are not usually employed in the initial stage of macular edema, particularly so in the stages when the decrease of vision is comparatively small. Accordingly, a drug treatment comparatively easily applicable from the early stages of the disease has been also demanded under the present circumstances.